I use my polymerase so quickly, I keep it at 4C. I have no fear of
leaving it in the fridge at all, and I'd say it stays okay at that
temperature for at least a month. I really doubt your problem is with
your enzyme. You need to mooch some reagents and DNA from someone that
you know has gotten them to work before and use that as the control
instead of what comes in the kit. Then when you know what you are
doing, move onto your own samples.
Sugar Beth Wapelhorst
Virginia Mason Research Center
Seattle
bethw at hebron.connected.com